do more expensive hand sanitizers inhibit bacterial proliferation better than less expensive ones?
DESCRIPTION
Do More Expensive Hand Sanitizers Inhibit Bacterial Proliferation Better Than Less Expensive Ones?. By: Henry Microbe Grade 7. Question / Problem. To determine which hand sanitizer will inhibit the proliferation of Escherichia coli ( E. coli ) for the lowest cost. Background Research. - PowerPoint PPT PresentationTRANSCRIPT
Do More Expensive Hand Sanitizers Inhibit
Bacterial Proliferation Better Than Less Expensive Ones?
By: Henry MicrobeGrade 7
Question / Problem
To determine which hand sanitizer will inhibit the proliferation of Escherichia coli (E. coli ) for the lowest cost.
Background ResearchA. Bacteria
1. Kingdom a. Eubacteria2. Prokaryotic Cells3. Methods of Classifying Bacteria
a. Shape 1. Coccus - Round
2. Bacillus - Rod 3. Spirillum - Spiral
b. Gram Staining 1. Gram + = purple2. Gram - = red
c. Clustering / Grouping 1. Diplo= two bacteria2. Strepto= chain of bacteria3. Staphylo= cluster of bacteria
4. E. coli A. Bacillus bacteria B. Gram - C. Normally found in the intestines of animals D. Diseases Caused by E. coli 1. Urinary Tract Infection 2. Diarrhea 3. Nausea 4. Possible Death
HypothesisAs the price of the hand sanitizer increases its ability to inhibit bacterial proliferation will increase.
VariablesResponding / Dependent
Constants
•1- Pure slant of E. coli•21- Sterile Tryptic Soy Agar (TSA) plates•84 - Sterile blank discs •Incubated at 37° C •Incubator used •Method of determining the average zone of inhibition
Nuisance
• Minor fluctuations in temperature and humidity in the incubator•Age & viability of the E. coli•Irregular zones of inhibition
The hand sanitizers being tested
Swan, Germ-x Aloe, Purell Adv., Germ-x Foaming, Germ-x
The ability of the hand sanitizers to inhibit bacterial proliferation
Manipulated / Independent
Materials Used• Pen• Paper• Incubator• 21 Sterile Tryptic Soy Agar (TSA) Petri Dishes• 84 Sterile Blank Discs • Sterile Saline Water (H20)• Hydrogen Peroxide (H202)• Sterile Latex Gloves• Sterile Tweezers• Sterile Beakers• Black Sharpie Marker• .22µm Millex Millipore Filter• Goggles• Sterile Nutrient Broth• Hand Sanitizers Tested: Swan Brand $0.37/100mL Germ-x Aloe $0.55/100mL Purell Advance $1.13/100mL Germ-x Foam $1.19/100mL Germ-x $1.33/100mL
Experimental ProcedureStep 1
Obtain needed materials
Step 3Sterilize work area with Hydrogen Peroxide
Step 4 Inoculate 50mL of sterile nutrient broth solution with E. coli & incubate for 72 hours at 37 º C
Step 5Inoculate 21 Tryptic Soy agar plates from Step 2 with 1 mL of the nutrient broth/E. coli solution prepared in step 4
Step 6Dip a sterile disc into a sterile saline water solution(- Control)
Step 7 Place the sterile disc from Step 6 in the center of one of the quadrants on one of the TSA plates
Step 2Divide 21 Tryptic Soy agar (TSA) plates into 4 equal size quadrants
Step 8Repeat steps 6-7 using 3 more test discs
Step 9 Repeat steps 6-8 using 2 more TSA plates prepared in Step 2
Step 10Repeat Steps 6 – 9 for peroxide (+ Control) and each of the hand sanitizers being tested
Step 11Incubate all Petri dishes for 72 hrs. at 37 º C
Step 12Determine and record the average zone of inhibition for each of the sterile discs dipped in the solutions being tested
Determining the Average Zone of Inhibition for Hydrogen Peroxide (+
Control)
Sterile Disc Dipped in H₂O₂
Photo: A
Optional Slide
Which Hand Sanitizer Inhibits Bacteria the Best for the Lowest Cost?
Average Zone of Inhibition (mm)
Disc Tested Hydrogen
Peroxide (+ Control)
Sterile Saline (- Control)
Swan Brand ($0.37
/100 mL)
Germ X Aloe
($0.55 /100mL)
Purell Adv. ($1.13 /100mL)
Germ X Foaming ($1.19 /100mL)
Germ X ($1.33/ 100mL)
1 7.5 0.0 5.0 4.0 6.0 4.0 6.0
2 10.5 0.0 8.0 4.5 1.0 3.5 6.0
3 10.0 0.0 3.5 5.0 13.5 3.5 5.5
4 11.0 0.0 6.5 4.5 11.0 3.5 4.5
5 10.5 0.0 8.5 5.0 7.0 3.5 4.5
6 6.0 0.0 10.0 5.0 7.5 4.0 4.0
7 9.0 0.0 1.0 1.0 7.0 3.5 5.0
8 10.0 0.0 8.0 5.0 4.5 4.0 5.0
9 10.5 0.0 1.0 4.5 5.5 3.5 4.5
10 10.5 0.0 4.0 4.5 6.0 4.0 5.0
11 10.0 0.0 5.5 5.0 4.5 3.5 5.0
12 9.5 0.0 6.0 5.5 9.0 1.0 6.0
Average 9.58 0.00 5.58 4.46 6.88 3.46 5.50
Hydro
gen
Pero
xide
(+
Con
trol)
Ster
ile S
aline
(- Con
trol)
Swan
Bra
nd
($0.
37
/
100
ml)
Germ
X A
loe
($0.
55
/100
ml
Pure
ll Adv
. ($1
.13
/1
00m
l)
Germ
Foa
ming
($1.
19
/100
ml)
Germ
X (
$1.3
3/10
0ml)
0123456789
1011 9.58
0.00
5.584.46
6.88
3.46
5.50
Which Hand Sanitizer Inhibits Bacteria the Best for the Lowest Cost?
Type and Price of Hand Santizer Tested
Avera
ge Z
on
e o
f In
hib
itio
n (
mm
)
Two Sample Independent T-Test Sterile Saline H
2O (- Control)
Significance Level = 0.05Claim: µ1 = µ2
Confidence Level = 95%
- Control vs. P-value Result
Swan Brand ($0.37 / 100 mL) 0.0023
Hypothesis Accepted
Germ X Aloe ($0.55 / 100 mL) 0.0450
Hypothesis Accepted
Purell Adv. ($1.13 / 100 mL) 0.0031
Hypothesis Accepted
Germ Foaming ($1.19 / 100 mL) 0.0420
Hypothesis Accepted
Germ X ($1.33 / 100 mL) 0.038
Hypothesis Accepted
Optional Slide
Two Sample Independent T-Test Hydrogen Peroxide (+ Control)
Significance Level = 0.05Claim: µ1 = µ2
Confidence Level = 95%
+ Control vs. P-value Result
Swan Brand ($0.37 / 100 mL) 0.0510
Hypothesis Rejected
Germ X Aloe ($0.55 / 100 mL) 0.0400
Hypothesis Accepted
Purell Adv. ($1.13 / 100 mL) 0.0148
Hypothesis Accepted
Germ Foaming ($1.19 / 100 mL) 0.0550
Hypothesis Rejected
Germ X ($1.33 / 100 mL) 0.0410
Hypothesis Accepted
Optional Slide
Based on the data I collected from my experiment I concluded that the data partially supported my hypothesis.
As the price of the hand sanitizer increases its ability to inhibit bacterial proliferation will increase.
Hand Sanitizer Cost/100 mL Average Zone of Tested Inhibition (mm)
Swan Brand $0.37 5.58 Germ-x Aloe $0.55 4.46 Purell Advance $1.13 6.88 Germ-x Foam $1.19 3.46 Germ-x $1.33 5.50
Conclusion
Actual Results
Hypothesis
H2O2 (+ Control) $0.35 9.58 Saline (- Control) $0.22 0.00
ConclusionBased on the Two Sample Independent T-Test that I performed on the data that I collected from my experiment I concluded that the data partially supported my hypothesis.
HypothesisAs the price of the hand sanitizer increases its ability to inhibit bacterial proliferation will increase.
Results
Hand Sanitizer Cost/ (P Value) (Hypothesis) (P Value) (Hypothesis) Tested 100mL
Swan Brand $0.37 0.0023 Accepted 0.0510 RejectedGerm-x Aloe $0.55 0.0450 Accepted 0.0400 AcceptedPurell Advance $1.13 0.0031 Accepted 0.0148 AcceptedGerm-x Foam $1.19 0.0420 Accepted 0.0550 RejectedGerm-x $1.33 0.0380 Accepted 0.0410 Accepted
H2O2 (+Control) $0.35 Saline (-Control) $0.22
Confidence Level = 95%
Saline Vs Sanitizer
Significance Level = 0.05
H2O2 Vs Samitizer
Conclusion Based on Statistical Analysis Optional Slide
Future Improvements / Changes
• Test more discs for each of the hand sanitizers being tested. (≥ 30 discs)
• Perform more trials (3 – 10 trials)
• Use a different protocol for determining the ability of hand sanitizers to inhibit bacterial proliferation.
• Purchase a greater number of hand sanitizers
Future Experiments / Extensions
• Design an experiment in order to determine the effect of hand sanitizers on a variety of different types of bacteria.
• Perform an experiment in order to determine the ability of natural herbs and spices to inhibit bacterial proliferation.
• Design and perform an experiment in order to determine whether bacteria will develop a resistance to various antibacterial chemicals.
• Perform an experiment in order to test the ability of different types of anti bacterial hand soaps to inhibit bacterial proliferation.
• Design and perform a similar experiment with hand soap
Real Life Applications
• The results obtained from my experiment could be used by cafeterias, restaurants, and hospitals to purchase the least expensive but most effective hand sanitizer.
• The results obtained from my experiment could assist my family to purchase the least expensive and most effective hand sanitizer for home use.
• This information could assist retailers in determining the most effective hand sanitizer to purchase for the least cost.
Bibliography of Sources "Clinical Infectious Diseases." Consumer Antibacterial Soaps: Effective or Just Risky? N.p., n.d. Web. 05 Dec. 2013.
"On the Structure of Eukaryotic, Prokaryotic, and Viral Chromatin." On the Structure of Eukaryotic, Prokaryotic, and Viral Chromatin. N.p., n.d. Web. 05 Dec. 2013.
"Zone of Inhibition." - Definition from Biology-Online.org. N.p., n.d. Web. 04 Feb. 2014.
"10-2 The Antibiotic Disk Sensitivity Test." Microbiology Labs. N.p., n.d. Web. 05 Feb. 2014.
"Escherichia Coli." Wikipedia. Wikimedia Foundation, 27 Jan. 2014. Web. 05 Feb. 2014.
"Wash Your Hands." Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 11 Dec. 2013. Web. 03 Feb. 2014.
Gram Staining ProcedureProcedure:
A. Slant Cultures
1. Prepare and heat-fix smears. 2. Prepare the smears of S. epidermidis and N. sicca on a second slide. Heat-fix. 3. Stain the slides as follows: a. Flood the crystal violet for one minute. b. Pour off excess dye and wash gently in tap water and drain the slide against a paper towel. c. Expose the smears to Gram's iodine for one minute by washing with iodine, then adding more iodine and leaving it
on the smear until the minute is over. d. Wash with tap water and drain carefully. (Do not blot.) e. Wash with 95% alcohol for 30 seconds. f. Wash with tap water at the end of the 30 seconds to stop the decolorization. Drain. g. Counterstain with 0.25% safranin for 30 seconds. h. Wash, drain, blot, and examine under oil. i. Draw the cells showing morphology, grouping, and relative
sizes. Color a few of the cells of each bacterial species to show the Gram reaction. j. Save these slides and the ones from parts B & C of this exercise to use at the next lab period.
Optional Slide
Active Ingredients
Hand Sanitizer Active Ingredient Percentage
Swan Brand($0.37/100mL) Ethyl Alcohol 65% Germ-x Aloe($0.55/100mL) Ethyl Alcohol 62%
Purell Advance($1.13/100mL) Ethyl Alcohol 70%
Germ-x Foaming($1.19/100mL) Benzalkonium Chloride 0.13%
Germ-x($1.33/100mL) Ethyl Alcohol 63%
Optional Slide
Sterile Saline Water (- Control)
Optional Slide Photo: B